Eyes

眼睛
  • 文章类型: Journal Article
    背景:凹陷的眼睛已成为眶周区域美学的最重要目标。纵观历史,已经强调了轨道周围区域的美学,并且已经描述了与该区域相关的各种手术技术。这些技术中的大多数仅提供软组织解决方案;因此,可能需要额外的外科手术.我们研究的目的是介绍一种内窥镜眶上剃刮(SOS)技术,用于治疗眼睛凹陷的人。
    方法:在2020年至2021年之间,34名患者(30名女性,4名男性;平均年龄36.2岁)用我们描述的技术治疗眼睛凹陷。所有患者在全身麻醉下接受了内窥镜SOS程序。
    结果:共有34名患者(30名女性和4名男性),23-59岁(平均=36.2岁),接受了内窥镜SOS程序。平均随访时间为13个月(范围:12-16个月)。术后,所有患者的侧凸性均有显著改善.在对照访问中进行的身体检查显示,任何患者均无功能问题,也没有可见或可触知的不规则或轮廓畸形。没有遇到关于SOS程序的并发症。
    结论:与在眼睛凹陷的患者中使用的其他技术相比,此处描述的技术提供了侧向凸度的显着改善。不需要额外的眼睑介入。与文献中先前描述的技术不同,在骨骼结构中进行干预,从而提供更准确的结果。
    方法:本期刊要求作者为每篇文章分配一定程度的证据。对于这些循证医学评级的完整描述,请参阅目录或在线作者说明www。springer.com/00266.
    BACKGROUND: Sunken eyes have become a most important target of periorbital area aesthetics. Throughout history, the aesthetics of the periorbital region have been emphasized, and various surgical techniques related to this region have been described. Most of these techniques provide only soft tissue solutions; therefore, additional surgical interventions may be required. The aim of our study was to introduce an endoscopic supraorbital shaving (SOS) technique for the treatment of individuals with sunken eyes.
    METHODS: Between 2020 and 2021, 34 patients (30 females, 4 males; mean age 36.2 years) with sunken eyes were treated with our described technique. All patients underwent an endoscopic SOS procedure under general anesthesia.
    RESULTS: A total of 34 patients (30 women and four men), aged 23-59 years old (mean = 36.2 years), underwent the endoscopic SOS procedure. The mean follow-up period was 13 months (range: 12-16 months). Postoperatively, significant improvement in lateral convexity was achieved in all patients. Physical examinations performed at the control visits revealed no functional problems in any patients and no visible or palpable irregularities or contour deformities. No complications were encountered regarding the SOS procedure.
    CONCLUSIONS: The technique described here provides significant improvement in lateral convexity compared to other techniques used in patients with sunken eyes. No additional eyelid intervention is needed. Unlike the techniques previously described in the literature, intervention is made in the bone structure, thereby providing more accurate results.
    METHODS: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    运动视觉是一个多学科的兴趣,旨在提高视觉系统的性能,以实现实践运动的好处,以及日常生活和预防保健。运动员练习的训练类型,他或她的身体状况,认知水平,和水平的疲劳状况影响的速度的反应时间和,因此,电机响应速度。特定的正交练习,使用技术设备,通过使用不稳定平台和双任务范式来恢复静态和动态姿势稳定性可以帮助达到预期的效果。这项对运动视觉的系统回顾的目的是评估现有的关于运动视觉的总体文献,特别注意视觉训练的效果及其在不同运动以及康复和预防环境中的应用。我们分析了1950年至2023年已发表的有关运动视觉在运动表现中的作用的英语语言研究。我们搜索了Medline数据库。PRISMA2020清单用于评估本次审查的透明度和可重复性。用Jadad量表对登记的论文进行了评估,Amstar2量表和纽卡斯尔-渥太华量表。25(16项研究,5评论,2评论,1社论,1份描述性论文)在476项研究中符合纳入标准。由于样本年龄的差异,不同的技术,研究参与者的治疗方法和不可评估文章的发现,未进行荟萃分析.本综述的局限性在于单一数据库研究,分析的研究包含无统计学代表性的样本量和缺乏对照组.没有标准化的测试来衡量性能。研究表明,视觉技能的发展可以使运动员预防损伤,可以改善任何年龄的运动表现和运动功能,即使视觉系统受损,也能获得自适应运动行为,由于任务重复和手势的熟悉。我们打算确定一种多学科方法和一种手动治疗方案,以优化运动视觉中涉及的电路,以增加所实现的结果,但为此还需要进一步的研究。
    Sport Vision is a speciality of multidisciplinary interest aimed at improving the performance of the visual system to achieve benefits in practiced sports, as well as in daily life and in preventive care. The type of training practiced by the athlete, his or her physical condition, cognitive level, and level of fatigue condition affects the speed of the reaction time and, consequently, the speed of motor response. Specific orthoptic exercises, the use of technological devices, the recovery of static and dynamic postural stability by using unstable platforms and the dual-task paradigm can help to achieve the expected results. The aim of this systematic review of Sport Vision was to assess the overall existing literature on Sport Vision, paying particular attention to the effects of visual training and its application in different sports and in rehabilitation and preventive settings. We analysed published English language studies about the role of sport vision in athletic performance from 1950 to 2023. We searched through the Medline database. The PRISMA 2020 checklist was used to assess the transparency and reproducibility of this review. The enrolled papers were evaluated with the Jadad Scale, Amstar 2 Scale and Newcastle-Ottawa Scale. 25 (16 studies, 5 reviews, 2 comments, 1 editorial, 1 descriptive paper) out of 476 studies met the inclusion criteria. Due to the variability in the age of the samples, the different techniques, the treatments among the participants in the studies and the finding of non-evaluable articles, a meta-analysis was not conducted. The limitations of this review are the single database research, the studies analyzed contain a non-statistically representative sample size and the lack of a control group. There is no standardized test to measure performance. It was shown that the development of visual skills can benefit athletes in injury prevention, and can lead to improved sports performance and motor function at any age, acquiring adaptive motor behaviour even when the visual system is impaired, due to task repetition and familiarity of the gesture. We intended to identify a multidisciplinary approach and a manual treatment scheme to optimize the circuitry involved in sport vision in order to increase the results that are achieved, but further studies will be needed to this end.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    身体吸引力深刻地影响着广泛的生活经历和结果,眼睛是身体吸引力的重要决定因素。我们调查了眼睛的特定特征-瞳孔大小-是否会影响感知的吸引力。我们提出了竞争性的理论预测,即扩张(较大)还是收缩(较小)的瞳孔应该表现出更多的身体吸引力。年轻的特征往往很有吸引力(即,neoteny),瞳孔大小在整个生命周期内减小,因此,扩大(扩大)的瞳孔可能更有吸引力作为青年的信号。或者,缩小的(小)瞳孔可能更有吸引力,因为,通过揭示更多的虹膜,它们增加了眼睛的颜色和亮度。本实验表明,当瞳孔收缩时,人们显得更有吸引力(实验1-3)。这种效果在黑白图像中同样大,表明颜色本身对于效果不是必需的(实验4)。相反,缩小的瞳孔使眼睛看起来更明亮,这反过来又使脸更有吸引力(实验5),即使在控制眼睛看起来多彩的时候(实验6)。这些结果将缩小的瞳孔确定为增强吸引力的新颖面部特征。
    Physical attractiveness profoundly affects a broad array of life experiences and outcomes, and the eyes are an important determinant of physical attractiveness. We investigated whether a particular feature of the eyes - pupil size - affects perceived attractiveness. We present competing theoretical predictions of whether dilated (larger) or constricted (smaller) pupils should appear more physically attractiveness. Youthful features tend to be attractive (i.e., neoteny), and pupil size decreases across the lifespan, so dilated (enlarged) pupils may be more attractive as a signal of youth. Alternatively, constricted (small) pupils may be more attractive because, by revealing more of the iris, they increase both color and brightness of the eyes. The present experiments demonstrate that people appear more attractive when their pupils are constricted (Experiments 1-3). This effect is equally large with black-and-white images, indicating that color per se is not necessary for the effect (Experiment 4). Rather, constricted pupils make eyes appear brighter, which in turn renders the face more attractive (Experiment 5), even when controlling for how colorful the eyes appear (Experiment 6). These results identify constricted pupils as a novel facial feature that enhances attractiveness.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    背景:商业妥布霉素眼用溶液经常用于经验治疗马的眼部疾病,尽管主要用于人类。已经注意到,妥布霉素MIC90浓度(微生物生长的90%的最小抑制浓度)在局部施用后迅速下降。假设用驴眼泪的pH值调节经验使用的妥布霉素眼用溶液-为人类使用制备-的pH值。可以增加药物的生物利用度,并随后改善其对房水的渗透。因此,这项研究旨在评估根据经验使用的妥布霉素眼用溶液的pH调节对驴(Equusasinus)的眼泪和房水中MIC90浓度的影响。该研究对6只(n=6)临床健康的驴进行。在每一头驴中,随机选择一只眼睛接受210μg妥布霉素的商业妥布霉素(CT),并用作阳性对照(C组,n=6)。另一只眼(治疗眼)接受210µg改良妥布霉素眼用溶液(MT)(T组,n=6)。收集泪液和房水样本5-,10-,15-,30-min,1-,2-,4-,和6小时后滴注。
    结果:在8.26的pH下修改实验使用的商业妥布霉素眼用溶液在驴中的pH提高了药物的生物利用度。从马眼中分离出的最危险细菌的MIC90,例如铜绿假单胞菌(MIC90=128µg/ml)和金黄色葡萄球菌(MIC90=256µg/ml)被早期(滴注后5分钟)和更长的时间用改良的妥布霉素溶液覆盖驴眼泪(239-342分钟)和房水(238-330分钟)。
    结论:调节市售妥布霉素眼用溶液的pH,兽医根据经验在pH值为8.26时治疗驴的眼科感染,与驴的眼泪pH值等渗,导致泪液和房水中的妥布霉素浓度更高,持续时间更长。
    BACKGROUND: Commercial tobramycin ophthalmic solution is frequently used empirically to treat ocular disorders in equines, despite being primarily formulated for use in humans. It has been noted that tobramycin MIC90 concentration (minimal inhibitory concentration to 90% of microbial growth) rapidly declined following topical administration. It is hypothesized that adjustment of the pH of the empirically used tobramycin ophthalmic solution -prepared for human use- with the pH of the tears of donkeys, could increase the bioavailability of the drug and subsequently improve its penetration to the aqueous humor. Therefore, this study aimed to evaluate the impact of pH adjustment of the empirically used tobramycin ophthalmic solution on MIC90 concentration in tears and aqueous humor of donkeys (Equus asinus). The study was conducted on six (n = 6) clinically healthy donkeys. In each donkey, one eye was randomly selected to receive 210 µg tobramycin of the commercial tobramycin (CT) and used as a positive control (C group, n = 6). The other eye (treated eye) received 210 µg of the modified tobramycin ophthalmic solution (MT) (T group, n = 6). Tears and aqueous humor samples were collected 5-, 10-, 15-, 30- min, and 1-, 2-, 4-, and 6 h post-instillation.
    RESULTS: Modifying the pH of the empirically used commercial tobramycin ophthalmic solution in donkeys at a pH of 8.26 enhanced the drug\'s bioavailability. The MIC90 of the most hazardous bacteria isolated from equines\' eyes such as Pseudomonas aeruginosa (MIC90 = 128 µg/ml) and Staphylococcus aureus (MIC90 = 256 µg/ml) was covered early (5 min post-instillation) and over a longer period in donkey tears (239-342 min) and aqueous humor (238-330 min) with the modified tobramycin solution.
    CONCLUSIONS: Adjustment of the pH of the commercial tobramycin ophthalmic solution, empirically used by veterinarians to treat donkeys\' ophthalmic infections at a pH of 8.26, isotonic with the donkeys\' tears pH, resulting in higher concentrations of tobramycin in tears and aqueous humor for a longer time.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    纳米酶,以它们的纳米级尺寸和类似酶的催化活性为特征,表现出不同的治疗潜力,包括抗氧化,抗炎,抗微生物,和抗血管生成作用。这些特性使它们在纳米医学中具有很高的价值,特别是眼部治疗,绕过全身输送的需要。纳米酶在解决多因素眼部疾病方面显示出重大希望,特别是那些受氧化和炎症影响的人,比如干眼病,和年龄相关性黄斑变性。他们的小尺寸,再加上它们易于修改和集成到软材料中,促进眼屏障的有效渗透,从而能够在眼睛内进行靶向或延长治疗。这篇综述致力于探索与氧化和炎症密切相关的眼部疾病,阐明纳米酶在管理这些条件中的作用。此外,最近的研究阐明了纳米酶在眼部治疗中的高级应用,以及它们与用于疾病管理的软材料的整合,正在讨论。最后,这篇综述概述了未来研究的方向,旨在弥合纳米酶研究和临床应用之间的差距。本文受版权保护。保留所有权利。
    Nanozymes, characterized by their nanoscale size and enzyme-like catalytic activities, exhibit diverse therapeutic potentials, including anti-oxidative, anti-inflammatory, anti-microbial, and anti-angiogenic effects. These properties make them highly valuable in nanomedicine, particularly ocular therapy, bypassing the need for systemic delivery. Nanozymes show significant promise in tackling multi-factored ocular diseases, particularly those influenced by oxidation and inflammation, like dry eye disease, and age-related macular degeneration. Their small size, coupled with their ease of modification and integration into soft materials, facilitates the effective penetration of ocular barriers, thereby enabling targeted or prolonged therapy within the eye. This review is dedicated to exploring ocular diseases that are intricately linked to oxidation and inflammation, shedding light on the role of nanozymes in managing these conditions. Additionally, recent studies elucidating advanced applications of nanozymes in ocular therapeutics, along with their integration with soft materials for disease management, are discussed. Finally, this review outlines directions for future investigations aimed at bridging the gap between nanozyme research and clinical applications.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    非视觉视蛋白是在许多动物的眼睛和其他组织中表达的跨膜蛋白。当与光敏发色团配对时,非视觉视蛋白形成涉及各种非视觉的光色素,光检测功能,包括昼夜节律调节,寻求光的行为,和季节性反应。在这里,我们研究了无双两栖动物(青蛙和蟾蜍)中非视觉视蛋白基因的分子进化。我们测试了几种进化假设,包括由于夜间祖先而导致的非视觉视蛋白的预测损失,以及由于不同无神经生态的环境光变化而导致的非视觉视蛋白的潜在功能差异。使用81个物种的全眼转录组,结合基因组,多组织转录组,并独立注释了来自另外21个物种的基因,我们确定哪些非视觉视蛋白存在于无性系基因组中,以及那些也在眼睛中表达的视蛋白,比较基因之间的选择性约束,并通过比较离散生态类之间的选择来检验潜在的适应性进化。在基因组层面,我们恢复了所有18种祖先脊椎动物的非视觉视蛋白,表明在祖先的夜间四足动物中,无神经显示出最低的视蛋白基因丢失量。我们一致地发现了14种非视觉视蛋白在无脑眼中的表达,并在这些基因的子集中检测到了阳性选择。我们还发现,在不同活动期的青蛙中,作用于非视觉视蛋白的选择性约束发生了变化,栖息地,分布,生活史,和瞳孔形状,这可能反映了功能适应。尽管许多非视觉视蛋白仍然知之甚少,这些发现提供了对这些基因在无性系中的多样性和进化的见解,填补了我们对脊椎动物视蛋白的理解的重要空白,并为未来研究它们跨分类群的功能进化奠定了基础。
    Nonvisual opsins are transmembrane proteins expressed in the eyes and other tissues of many animals. When paired with a light-sensitive chromophore, nonvisual opsins form photopigments involved in various nonvisual, light-detection functions including circadian rhythm regulation, light-seeking behaviors, and seasonal responses. Here, we investigate the molecular evolution of nonvisual opsin genes in anuran amphibians (frogs and toads). We test several evolutionary hypotheses including the predicted loss of nonvisual opsins due to nocturnal ancestry and potential functional differences in nonvisual opsins resulting from environmental light variation across diverse anuran ecologies. Using whole-eye transcriptomes of 81 species, combined with genomes, multitissue transcriptomes, and independently annotated genes from an additional 21 species, we identify which nonvisual opsins are present in anuran genomes and those that are also expressed in the eyes, compare selective constraint among genes, and test for potential adaptive evolution by comparing selection between discrete ecological classes. At the genomic level, we recovered all 18 ancestral vertebrate nonvisual opsins, indicating that anurans demonstrate the lowest documented amount of opsin gene loss among ancestrally nocturnal tetrapods. We consistently found expression of 14 nonvisual opsins in anuran eyes and detected positive selection in a subset of these genes. We also found shifts in selective constraint acting on nonvisual opsins in frogs with differing activity periods, habitats, distributions, life histories, and pupil shapes, which may reflect functional adaptation. Although many nonvisual opsins remain poorly understood, these findings provide insight into the diversity and evolution of these genes across anurans, filling an important gap in our understanding of vertebrate opsins and setting the stage for future research on their functional evolution across taxa.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    城市地区绿色空间的温度升高和破碎化可能会导致昆虫功能特征的变化。感觉系统可能会发生这种形态变化,以前据报道,在非城市环境中,它们容易随着栖息地特征而变化。这里,我们沿着米兰(意大利)的城市化梯度测量了蜜蜂Halictusscabiosae和Osmiacornuta和黄蜂Polistesdominula的视觉和触角感觉系统相关的特征。我们假设碎片可以过滤更好的视觉属性,更高的温度可以过滤更少的热受体和更多的嗅觉毛发。在控制身体尺寸的同时,结果表明,在所有物种的一个或多个性状中,对城市化的反应是微妙但可观的,虽然并不总是支持我们的假设。O.cornuta在更零散的部位显示出较高的眼孔密度和较小的眼孔直径(与更好的视觉分辨率相关),以及较热部位的热受体略少,与我们的两个预测一致。另一方面,H.scabiosae的触角略小,P.dominula在温暖的位置眼睛较小,黄蜂在更零散的区域也有更小的触角和第9鞭球。也许在这两个物种中,较高的温度比身体其他部分更快地加速感觉系统的发育。我们的结果代表了城市化对蜜蜂和黄蜂的视觉和触角感觉系统的影响的第一个证据,并强调了这种影响可能涉及比以前观察到的更广泛的特征花束。
    Increased temperature and fragmentation of green spaces in urban areas could drive variations in functional traits of insects. Such morphological shifts may occur for sensory systems, which were previously reported to be prone to change with habitat characteristics in non-urban contexts. Here, we measured traits related to the visual and antennal sensory systems in the bees Halictus scabiosae and Osmia cornuta and the wasp Polistes dominula along an urbanisation gradient within Milan (Italy). We hypothesised that fragmentation could filter for better visual properties, and that higher temperature could filter for fewer thermoreceptors and more olfactory hairs. While controlling for body size, results show subtle but appreciable responses to urbanisation in one or more traits in all species, though not always supporting our hypotheses. O. cornuta shows marginally higher ommatidia density and smaller ommatidia diameter (associated with better visual resolution) in more fragmented sites, as well as marginally fewer thermoreceptors in hotter sites, in agreement with our two predictions. On the other hand, H. scabiosae has marginally smaller antennae and P. dominula has smaller eyes at warmer locations, and the wasp also has smaller antennae and 9th flagellomeres in more fragmented areas. Perhaps higher temperatures accelerate development of sensory system at higher speed than the rest of body in these two species. Our results represent the first evidence of urbanisation effects on the visual and antennal sensory systems of bees and wasps and underline how such effects may involve a much broader bouquet of traits then previously observed.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    暂无摘要。
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    背景:虽然它是可以治疗的,未矫正的屈光不正是全球视力损害的头号原因.单是这种眼睛状况,或与眼位错位一起,也会导致弱视,如果早期发现,也是可以治疗的,但仍发生在约4%的人口中。大规模视力筛查是解决这些问题的第一步,也是最关键的一步,但由于资源有限,在许多农村地区,视力筛查仍然是一个重大挑战。
    目的:我们的目的是对使用智能手机应用程序在眼部护理受限的地区增强视力筛查的可行性进行试点测试。
    方法:一项视力筛查计划被搭载在四川一个农村县的慈善夏令营计划中,中国。使用标准视力表对总共73名四年级和五年级学生进行了视敏度测试,然后使用2个智能手机应用程序(一个屈光应用程序和一个斜视应用程序,分别)由非专业人员。
    结果:总共73个中的5个(6.8%,95%CI2.3%-15.3%)的学生被发现至少一只眼睛的视力比20/20(最小分辨率角[logMAR]0的对数)差。在5名学生中,3根据屈光app主要具有屈光不正。根据斜视应用程序,其他2名学生有明显的斜视(一个具有72棱镜屈光度[PD]内斜视,一个具有33-PD外斜视)。没有明显斜视的学生也测量使用斜视应用程序在覆盖/揭开模式。中位盲区为0.0-PD(IQR2.9-PD内隐落至2.2-PD外隐落为)。
    结论:这项视力筛查研究的结果与眼科专业人员使用常规工具的其他基于人群的视力筛查研究的结果一致。智能手机应用程序很有前途,有可能用于大规模视力筛查,以识别弱视和近视控制的危险因素。智能手机应用程序可能对低成本视力保健的未来产生重大影响,特别是在资源有限和地理偏远的地区。
    BACKGROUND: While it is treatable, uncorrected refractive error is the number one cause of visual impairment worldwide. This eye condition alone, or together with ocular misalignment, can also cause amblyopia, which is also treatable if detected early but still occurs in about 4% of the population. Mass vision screening is the first and most critical step to address these issues, but due to limited resources, vision screening in many rural areas remains a major challenge.
    OBJECTIVE: We aimed to pilot-test the feasibility of using smartphone apps to enhance vision screening in areas where access to eye care is limited.
    METHODS: A vision screening program was piggybacked on a charity summer camp program in a rural county in Sichuan, China. A total of 73 fourth and fifth graders were tested for visual acuity using a standard eye chart and were then tested for refractive error and heterophoria using 2 smartphone apps (a refraction app and a strabismus app, respectively) by nonprofessional personnel.
    RESULTS: A total of 5 of 73 (6.8%, 95% CI 2.3%-15.3%) students were found to have visual acuity worse than 20/20 (logarithm of minimal angle of resolution [logMAR] 0) in at least one eye. Among the 5 students, 3 primarily had refractive error according to the refraction app. The other 2 students had manifest strabismus (one with 72-prism diopter [PD] esotropia and one with 33-PD exotropia) according to the strabismus app. Students without manifest strabismus were also measured for phoria using the strabismus app in cover/uncover mode. The median phoria was 0.0-PD (IQR 2.9-PD esophoria to 2.2-PD exophoria).
    CONCLUSIONS: The results from this vision screening study are consistent with findings from other population-based vision screening studies in which conventional tools were used by ophthalmic professionals. The smartphone apps are promising and have the potential to be used in mass vision screenings for identifying risk factors for amblyopia and for myopia control. The smartphone apps may have significant implications for the future of low-cost vision care, particularly in resource-constrained and geographically remote areas.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    关键的发育途径和基因网络是参与化学感觉的感觉细胞类型和结构形成的基础,视觉和机械感觉,这些感官输入可以激活。我们描述了三个主要脊索类群的选定物种中这些途径和基因网络的相似性和差异,柳叶刀,被衣动物,和脊椎动物,导致嗅觉受体的不同发育,眼睛,毛细胞和运动神经元。某些转录因子在柳叶刀和被膜中缺乏适当的位置表达,阻止了它们发育成脊椎动物样的嗅觉受体和眼睛,尽管它们会产生化学感觉和视觉的替代结构。柳叶刀和被膜缺乏与听觉刺激有关的机械感觉细胞,但是具有重力敏感器官和纤毛表皮感觉细胞,可能(并且在某些情况下显然确实如此)提供机械感觉,从而能够响应相对于周围水的运动。尽管功能类似于脊椎动物的前庭器官和侧线,由于脊椎动物毛细胞发育所依赖的关键转录因子Neurog和Atoh1/7的表达差异,同源性值得怀疑。因此,带有脊椎动物毛细胞的内耳和侧线可能代表了脊椎动物特有的主要进化进展。运动神经元在腹侧信号分子hedgehog/sonichedgehog的控制下在脊椎动物中发育(Hh,嘘),对抗由背侧信号分子介导的相反抑制作用。许多参与指定和分化运动神经元的Shh信号和下游基因的元素也由柳叶刀和被膜表现出来,但是脊椎动物的MNs范围更广,表明运动神经元分化程序具有更大的多样性。
    Key developmental pathways and gene networks underlie the formation of sensory cell types and structures involved in chemosensation, vision and mechanosensation, and of the efferents these sensory inputs can activate. We describe similarities and differences in these pathways and gene networks in selected species of the three main chordate groups, lancelets, tunicates, and vertebrates, leading to divergent development of olfactory receptors, eyes, hair cells and motoneurons. The lack of appropriately posited expression of certain transcription factors in lancelets and tunicates prevents them from developing vertebrate-like olfactory receptors and eyes, although they generate alternative structures for chemosensation and vision. Lancelets and tunicates lack mechanosensory cells associated with the sensation of acoustic stimuli, but have gravisensitive organs and ciliated epidermal sensory cells that may (and in some cases clearly do) provide mechanosensation and thus the capacity to respond to movement relative to surrounding water. Although functionally analogous to the vertebrate vestibular apparatus and lateral line, homology is questionable due to differences in the expression of the key transcription factors Neurog and Atoh1/7, on which development of vertebrate hair cells depends. The vertebrate hair cell-bearing inner ear and lateral line thus likely represent major evolutionary advances specific to vertebrates. Motoneurons develop in vertebrates under the control of the ventral signaling molecule hedgehog/sonic hedgehog (Hh,Shh), against an opposing inhibitory effect mediated by dorsal signaling molecules. Many elements of Shh-signaling and downstream genes involved in specifying and differentiating motoneurons are also exhibited by lancelets and tunicates, but the repertoire of MNs in vertebrates is broader, indicating greater diversity in motoneuron differentiation programs.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

公众号